Use meta key + wheel to zoom in/out (#769)

src/scene/index.ts

@@ -27,4 +27,4 @@ export {
   hasText,
 } from "./comparisons";
 export { createScene } from "./createScene";
-export { getZoomOrigin, getZoomTranslation } from "./zoom";
+export { getZoomOrigin, getZoomTranslation, getNormalizedZoom } from "./zoom";

src/scene/zoom.ts

@@ -28,3 +28,9 @@ export function getZoomTranslation(canvas: HTMLCanvasElement, zoom: number) {
     y: parseFloat(diffMiddleOfTheCanvas.y.toFixed(8)),
   };
 }
+
+export function getNormalizedZoom(zoom: number): number {
+  const normalizedZoom = parseFloat(zoom.toFixed(2));
+  const clampedZoom = Math.max(0.1, Math.min(normalizedZoom, 2));
+  return clampedZoom;
+}